1. Field of the Invention
The invention relates in general to a motion detection method and associated method, and more particularly to a motion detection method capable of performing motion detection without a motion vector and associated method.
2. Description of the Related Art
Accompanied with improvements of broadband transmission environments, high-quality video frame transmission is to become a future trend. As related hardware equipment with consumer-friendly prices gains prevalence, high-quality video services are now in higher demands. In order to efficiently and smoothly complete video frame transmissions under a limited bandwidth or capacity, video frames are necessarily compressed in a transmission process of the video frames.
Certain compression algorithms are implemented via a video encoder. In a video encoder, based on high correlations between video frames in a time-domain, a motion vector is directly placed in a macro block to be encoded according to a motion vector prediction technique to express a distance between the macro block and a most similar reference block in a reference frame. Thus, a data amount to be encoded in the encoding process can be significantly reduced. In fact, a considerable motion correlation exists between not only video frames but also neighboring macro blocks of a same video frame. Such characteristic may be employed by the video encoder for further reducing the data amount to be encoded. However, the motion detection cannot be performed in the event that the selected compression algorithm does not generate a motion vector.